Feature/network

CHANGELOG.md

@@ -7,17 +7,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-## [2.1.6] - 2025-07-30
 
 ### Changed
-- `Sink`, `Source` and `SourceAndSink` now accept multiple `flows` as `inputs` and `outputs` instead of just one. This enables to model more use cases using these classes.
-- Further, both `Sink` and `Source` now have a `prevent_simultaneous_flow_rates` argument to prevent simultaneous flow rates of more than one of their Flows.
+- `Sink`, `Source` and `SourceAndSink` now accept multiple `flows` as `inputs` and `outputs` instead of just one. This enables to model more use cases using these classes. [[#291](https://github.com/flixOpt/flixopt/pull/291) by [@FBumann](https://github.com/FBumann)]
+- Further, both `Sink` and `Source` now have a `prevent_simultaneous_flow_rates` argument to prevent simultaneous flow rates of more than one of their Flows. [[#291](https://github.com/flixOpt/flixopt/pull/291) by [@FBumann](https://github.com/FBumann)]
+
+### Added
+- Added `FlowSystem.start_network_app()` and `FlowSystem.stop_network_app()` to easily visualize the network structure of a flow system in an interactive dash web app. This is still experimental and might change in the future. [[#293](https://github.com/flixOpt/flixopt/pull/293) by [@FBumann](https://github.com/FBumann)]
 
 ### Deprecated
-- For the classes `Sink`, `Source` and `SourceAndSink`: `.sink`, `.source` and `.prevent_simultaneous_sink_and_source` are deprecated in favor of the new arguments `inputs`, `outputs` and `prevent_simultaneous_flow_rates`.
+- For the classes `Sink`, `Source` and `SourceAndSink`: `.sink`, `.source` and `.prevent_simultaneous_sink_and_source` are deprecated in favor of the new arguments `inputs`, `outputs` and `prevent_simultaneous_flow_rates`. [[#291](https://github.com/flixOpt/flixopt/pull/291) by [@FBumann](https://github.com/FBumann)]
 
 ### Fixed
-- Fixed testing issue with new `linopy` version 0.5.6 [[#296](https://github.com/PyPSA/linopy/pull/296) by [@FBumann](https://github.com/FBumann)]
+- Fixed testing issue with new `linopy` version 0.5.6 [[#296](https://github.com/flixOpt/flixopt/pull/296) by [@FBumann](https://github.com/FBumann)]
 
 ## [2.1.5] - 2025-07-08
 

examples/02_Complex/complex_example.py

@@ -182,6 +182,7 @@
     flow_system.add_elements(bhkw_2) if use_chp_with_piecewise_conversion else flow_system.add_elements(bhkw)
 
     pprint(flow_system)  # Get a string representation of the FlowSystem
+    flow_system.start_network_app()  # Start the network app. DOes only work with extra dependencies installed
 
     # --- Solve FlowSystem ---
     calculation = fx.FullCalculation('complex example', flow_system, time_indices)

flixopt/flow_system.py

@@ -61,6 +61,8 @@ def __init__(
 
         self._connected = False
 
+        self._network_app = None
+
     @classmethod
     def from_dataset(cls, ds: xr.Dataset):
         timesteps_extra = pd.DatetimeIndex(ds.attrs['timesteps_extra'], name='time')
@@ -241,6 +243,57 @@ def plot_network(
         node_infos, edge_infos = self.network_infos()
         return plotting.plot_network(node_infos, edge_infos, path, controls, show)
 
+    def start_network_app(self):
+        """Visualizes the network structure of a FlowSystem using Dash, Cytoscape, and networkx.
+        Requires optional dependencies: dash, dash-cytoscape, networkx, werkzeug.
+        """
+        from .network_app import DASH_CYTOSCAPE_AVAILABLE, VISUALIZATION_ERROR, flow_graph, shownetwork
+
+        warnings.warn(
+            'The network visualization is still experimental and might change in the future.',
+            stacklevel=2,
+            category=UserWarning,
+        )
+
+        if not DASH_CYTOSCAPE_AVAILABLE:
+            raise ImportError(
+                f"Network visualization requires optional dependencies. "
+                f"Install with: pip install flixopt[viz], flixopt[full] or pip install dash dash_cytoscape networkx werkzeug. "
+                f"Original error: {VISUALIZATION_ERROR}"
+            )
+
+        if not self._connected:
+            self._connect_network()
+
+        if self._network_app is not None:
+            logger.warning('The network app is already running. Restarting it.')
+            self.stop_network_app()
+
+        self._network_app = shownetwork(flow_graph(self))
+
+    def stop_network_app(self):
+        """Stop the network visualization server."""
+        from .network_app import DASH_CYTOSCAPE_AVAILABLE, VISUALIZATION_ERROR
+        if not DASH_CYTOSCAPE_AVAILABLE:
+            raise ImportError(
+                f'Network visualization requires optional dependencies. '
+                f'Install with: pip install flixopt[viz]. '
+                f'Original error: {VISUALIZATION_ERROR}'
+            )
+
+        if self._network_app is None:
+            logger.warning('No network app is currently running. Cant stop it')
+            return
+
+        try:
+            logger.info('Stopping network visualization server...')
+            self._network_app.server_instance.shutdown()
+            logger.info('Network visualization stopped.')
+        except Exception as e:
+            logger.error(f'Failed to stop the network visualization app: {e}')
+        finally:
+            self._network_app = None
+
     def network_infos(self) -> Tuple[Dict[str, Dict[str, str]], Dict[str, Dict[str, str]]]:
         if not self._connected:
             self._connect_network()